A painful heel syndrome (plantar fasciitis and/or Achilles tendinitis) was found in 33 among 150 patients suffering from a seronegative spondarthritis. The clinical and radiological manifestations of this syndrome were similar in the nosological entities included in the seronegative spondarthritis group. HLA-B27 antigen was found in 91% of the patients, radiological sacroliitis in 64% and an asymmetric peripheral arthritis in all cases. By contrast, Achilles tendinitis was not encountered in 220 cases of rheumatoid arthritis; plantar fasciitis was exceptional in the same cases.